Motor fuel composition

ABSTRACT

Motor fuel composition comprising a mixture of hydrocarbons in the gasoline boiling range containing a alkyl ammonium alkyl alkanephosphonate represented by the formula:   in which R is an aliphatic hydrocarbon radical having from about 8 to 22 carbon atoms, R&#39;&#39; is a lower aliphatic hydrocarbon radical having from 1 to 2 carbon atoms, R2 is an aliphatic hydrocarbon radical having from 8 to 20 carbon atoms or an aminoalkyl group of the structure NH2-(CH2)n- or an N&#39;&#39;-alkylaminoalkyl group of the structure R5-NH-(CH2)n where R5 is an aliphatic hydrocarbon radical from 8 to 20 carbon atoms and n is an interger from 2 to 6, and R3 and R4 are either one or both, hydrogen atoms or aliphatic hydrocarbon radicals having form 1 to 20 carbon atoms.

United States Patent 1 Schlicht et al.

l l MOTOR FUEL COMPOSITION [75] Inventors: Raymond C. Schlicht, Fishkill;

George W. Eckert, Wappingers Falls. both of NY.

[73] Assignee: Texaco lnc., New York. N.Y.

[22] Filed: June 10, 1974 [2]] Appl. No.: 477,716

152] U.S. Cl.. 44/72; 44/DlG. l; 44/DlG. 4; 252/392 {5|} Int. Cl C101 H26 [58] Field of Search 44/DlG. l, DIG. 4, 72; 252/392 [56] References Cited UNITED STATES PATENTS 2.563.506 8/1951 Werntz 44/72 3,228,758 H1966 Bauer 44/72 3,387.954 6/1968 Capowski 44/72 3.807.974 4/1974 Kerley ct al. 44/58 Primary E.raminerDaniel E. Wyman Assistant ExaminerY. H. Smith Attorney, Agent, or FirmT. H. Whaley; C. G. Ries; James J. OLoughlin July 22, 1975 [57] ABSTRACT Motor fuel composition comprising a mixture of hydrocarbons in the gasoline boiling range containing a alkyl ammonium alkyl alkanephosphonate represented by the formula:

in which R is an aliphatic hydrocarbon radical having from about 8 to 22 carbon atoms, R is a lower aliphatic hydrocarbon radical having from 1 to 2 carbon atoms, R is an aliphatic hydrocarbon radical having from 8 to 20 carbon atoms or an aminoalkyl group of the structure NH -(CH or an N'-alkylaminoalkyl group of the structure R -NH"QCH where R is an aliphatic hydrocarbon radical "from 8 to 20 carbon atoms and n is an interger from 2 to 6, and R and R are either one or both, hydrogen atoms or aliphatic hydrocarbon radicals having form 1 to 20 carbon atoms.

11 Claims, N0 Drawi ii gs MOTOR FUEL COMPOSITION BACKGROUND OF THE INVENTION 1. Field of the Invention Modern internal combustion engine design is undergoing important changes to meet new Federal standards concerning engine exhaust gas emissions. A major change in engine design recently adopted is the feeding of blow-by gases from the crankcase zone of the engine into the intake air supply to the carburetor rather than venting these gases to the atmosphere as in the past. A further change being adopted involves the recycling of a part of the exhaust gases to the combustion zone of the engine in order to effect a more complete combustion and to further reduce objectionable exhaust emissions. The recycled exhaust gases contain substantial amounts of deposit-forming substances which promote the formation of deposits in and around the throttle plate area of the carburetor. These deposits have the effect of restricting the flow of air through the carburetor at idle and at low speeds so that an overrich fuel mixture results. This condition produces rough engine idling and stalling, and serves to increase the harmful exhaust emissions which the engine design changes were intended to overcome.

Modern gasoline compositions are very highly refined products. Despite this, they contain minor amounts of impurities which can promote corrosion during the period that the bulk fuel is transported and stored and also in the fuel tank, fuel lines and carburetor of the motor vehicle. An acceptable motor fuel must contain an effective and compatible inhibitor to inhibit or prevent corrosion during transport and prior to its use in the engine.

2. Description of the Prior Art US. Pat. No. 3,793,199 discloses a lubricating oil composition containing an ammonium salt of alkyl alkanephosphonic acid.

US. Pat. No. 3,704,107 discloses a jet fuel composition containing a bis-(hydroxyalkyl) alkyl phosphonate as an antiwear additive.

US. Pat. No. 2,635,112 discloses a process for producing aminomethylphosphonic acid compounds and discloses the use thereof in gasoline and petroleum products as anti-oxidants and metal deactivators.

SUMMARY OF THE INVENTION A class of alkylammonium alkyl alkanephosphonates are provided as carburetor anti-icing agents and corrosion inhibitors when employed in a liquid hydrocarbon fuel for an internal combustion engine. These compounds, which are characterized by having two relatively long hydrocarbon radicals, including one attached to a phosphorus atom and one attached to a nitrogen atom, appear to be unique in their carburetor anti-icing and corrosion inhibiting properties. Similar compounds were found to be ineffective for providing a fuel composition having the properties of the composition of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The alkylammonium alkyl alkanephosphonate additive component of the fuel composition of the invention is represented by the formula:

in which R is an aliphatic hydrocarbon radical having from about 8 to 22 carbon atoms, R is a lower aliphatic hydrocarbon radical having from 1 to 2 carbon atoms, R is an aliphatic hydrocarbon radical having from 8 to 20 carbon atoms or an aminoalkyl group of the structure NH (CH or N-alkylaminoalkyl group of the structure R -NH-(CH where R is an aliphatic hydrocarbon radical from 8 to 20 carbon atoms and n is an integer from 2 to 6, and R and R are either one or both, hydrogen atoms or aliphatic hydrocarbon radicals having from 1 to 4 carbon atoms.

A preferred alkylammonium alkyl alkanephosphate is one conforming to the above formula in which R and R aliphatic-hydrocarbon radical having from 10 to 18 carbon atoms.

The prescribed alkylammonium alkyl alkanephosphonate is a known material. It can be prepared by reacting an alkanephosphonate diester with an amine according to the following formula:

in which R, R, R R and R have the values noted above. This is a straightforward non-catalytic reaction and can be conducted at a moderately elevated temperature over a short reaction period. A temperature substantially greater than C., e.g. 130C. is preferred while greater than 150C. would usually be un necessary. Reaction times of 25 hours are normally employed, although shorter times, e.g. 15 minutes to 1 hours, are often sufficient. An inert, nonpolar solvent such as a hydrocarbon, can be employed to facilitate the reaction. The amine reactant may be used in substantial excess, e.g. from 1 to 2 moles of amine per mole of the alkanephosphonate diester, without changing the reaction as more fully set forth in US. Pat. No. 3,793,199.

The following examples illustrate the method for preparing an alkylammonium alk-yl alkanephosphonate employed in the present fuel composition.

EXAMPLE I C1445 sec. Alkylmethylammonium methyl-n-tetradecylphosphonate 55 grams (0.255 mole) of C1445 sec. alkyl amine and grams (0.255 mole) of dimethyl n-tetradecylphosphonate were added to a reaction vessel. The mixture was heated to a temperature in the range from about to C. and maintained under these reaction conditions for about 2.5 hours. Recovery of entire product was effected without further treatment or purification.

Analysis of the product was as follows:

Found Calc.

% Nitrogen 2.3 2.3 Phosphorus 5.8 5.1 Total Acid No. 75 92"" ""Calc. for one acidic H formed per phosphorus atom EXAMPLE ll n-Dodecylmethylammonium methyl-n-tetradecylphosphonate 46 grams (0.25 mole) of n-dodecylmonoamine (Armeen 12D) and 87 grams (0.25 mole) of dimethyl tetradecylphosphonate were mixed in a reaction vessel. The mixture was heated to a temperature in the range from about 1 to 125C. and maintained under these condisions for 4 hours. On completion of the reaction the n-dodecylamine ammonium salt of monomethyl n-C alkanephosphonate was recovered without further treatment. and analyzed as follows:

Found Calc.

% Nitrogen 2.5 2.6 Phosphorus 6.6 5.8 Total Acid No. 98 105 EXAMPLE lll N'-Dodecylaminopropylmethylammonium n-tetradecylphosphonate 50g (0.206 mole) N'-dodecylaminopropylamine (Armours Duomeen C) 65g (0.206 mole) dimethyl n-tetradecanephosponate, and 100 ml. toluene were added to a reaction vessel. The mixture was heated to a temperature in the range of ll9l25C. and maintained there for about 3 hours. The reaction mixture was filtered and ditilled to l00C./l4mm. to remove the toluene. Product recovery was 99 percent of theory.

Analysis of the product were as follows:

methyl 0 Found Cale.

%.N 4.5 5.0 %.P 5.3 5.5 Total Acid No. 90 100 EXAMPLE [V N-Octadecylaminopropylmethylammonium methyl n-tetradecanephosphonate 160g (0.5 mole) N'-octadecylaminopropylamine (Gen. Mill's -Diam 26) was freed of water by azeotropic distillation with 200 ml benzene. Then 144g (0.45 mole) dimethyl n-tetradecanesphosphonate was added, and the solvent was removed by distilling up to lC. This mixture was heated 3 hrs. at 120C., and then vacuum distilled at 57C. max. at mm. to complete the solvent removal.

Analysis of the product were as follows:

Found Calc.

%.N 4.2 4.6 %.P 4.2 4.6 TAN 82 83 EXAMPLE V N-Octadecylaminopropylmethylammonium n-octadecanephosphonate 40g (0.125 mole) N'-octadecylaminopropylamine was freed of water by toluene azeotroping. Then 43 g (0.10 mole) dimethyl n-octadecanephosphonate was added, and the solution was refluxed at ll9l25C. for 3 hrs. The final reaction mixture was distilled to C. at 14 mm. to remove solvent.

Analysis of the product were as follows:

methyl Found Cale.

%.N 3.8 4.2 %.P 3.9 3.8 Total Acid No. 69. 68.

EXAMPLE Vl N-Tetradecyltrimethylammonium methyl n-tetradecanephosphonate 48 g (0.2mo1e) n-tetradecyldimethylamine (Armour), 64g. (0.2 mole) dimethyl n-tetradecanephosphonate and 100 ml. toluene was refluxed 8 hrs. at 121-6C. After standing to cool, a crystalline product (A) was filtered off and air-dried to yield 48 g white solid. The filtrate, after 6 hrs. further reaction at C, generated no more solid product. The solvent was stripped off at 90C. 16mm. to obtain 64 g. amber liquid product (B).

Analysis were as follows:

VI A Vl B Calculated %N 2.6 2.2 2.5 %P 5.67 5.4 5.54 Total Acid No. 0.28 16 0 Examples of other suitable alkylammonium alkyl alkanephosphonate additives for the fuel composition of this invention include:

Dodecylmethylammonium methyl-noctadecylphosphonate,

Octadecylethylammonium methyl-noctadecylphosphonate,

Tetradecylbutylammonium ethyl-n-hexadecylphosphonate,

The prescribed alkyl ammonium alkyl alkanephosphonate of the invention is employed in the gasoline fuel composition in a concentration to provide both effective carburetor detergency and corrosion inhibiting properties. In general, an effective concentration of the additive ranges from about 0.0005 to 0.l weight percent with a preferred concentration ranging from about 0.002 to 0.075 weight percent. The limits of the preferred range corresponded respectively to about 2 and 200 PTB (pounds of additive per 1000 barrels of gasoline).

Any gasoline suitable for a spark-ignited, internal combustion engine can be used in the practice of this invention. In general, the base fuel will consist ofa mixture of hydrocarbons in the gasoline boiling range, i.e. boiling from about 75 to 450F. The hydrocarbon components can consist of paraffinic, naphthenic, aromatic and olefinic hydrocarbons. This gasoline can be obtained naturally or it can be produced by thermal or catalytic cracking and/or reforming of petroleum hydrocarbons. The base fuel will generally have a Research Octane Number above 80 and up to about 102 with the preferred range being from about 85 to 100.

The prescribed alkyl ammonium alkyl alkanephosphonate additive of the invention was tested for its effectiveness in gasoline in the Colonial Pipeline Rust Test and the Carburetor Icing Test described below:

COLONIAL PIPELINE RUST TEST A steel spindle, 3 3/16 inches long and one half inch pump equipped so that cool moisture-saturated air from an ice tower is drawn through a sample glass tube gasoline carburetor. The gasoline sample is placed in a sample bottle and is drawn into the glass carburetor through a 20 gage hypodermic needle. Evaporation of the gasoline in the gas tube further cools the cold moist air with resulting ice formation on the throttle plate. The formation of ice on the throttle plate causes an engine to stall and it has been found that this condition is equivalent to a pressure drop across the throttle plate of about 0.9 inches of mercury and the time required to reach this pressure drop is noted. The vacuum pump is adjusted to give a vacuum of 1.8 inches of mercury and the test is run until either a pressure of 2.3 inches mercury has been reached or the run has continued for 300 seconds. Since, with most fuels, this pressure drop is reached in l to 4'minutes, 300 seconds is the usual maximum time for a'run. An effective carburetor antiicing fuel additive is judged on basis of comparison with a blank (base fuel), since the level of numbers from this test tend to vary somewhat.

The Base Fuel employed in the following examples was a premium grade gasoline having a Research Octane Number of about 100 and containing C. of tetraethyl lead pef gallon. This gasoline consisted of about 25 percent aromatic hydrocarbons, l0 percent olefinic hydrocarbons and 65 percent paraffinic hydrocarbons and boiled in the range from about 90F. to 380F.

The test results obtained with the fuel composition of the invention and with comparison fuels are set forth in Table I below:

TABLE I COLONIAL PIPELINE RUST AND ICING TESTS Colonial Pipe- Carburetor line Rust Test Icing Test Run Additive & Cone. lbs/I000 bbls. Rust Seconds to 0.9I-lg.

l. Base Fuel None 90 83 2. Reaction Product of N Butylamine and dimcthyl-n-C ,-phosphonatc l6 PTB 92 3. Reaction Product of N Butylamine and dimethyl-n-C -phosphonate 8 PTB 70 I33 4. Reaction Product of alkenyl succinimide" and dimethyl n-C phosphonate l6 PTB 2O 49 5. 9 PTB 30 64 6. Example I I6 PTB 0 300 7. Example I 8 PTB 0 380 8. Example Ill 32 PTB 0 300 9. Example III 8 PTB Few Specs. l0. Example VI-A l6 PTB 0 300 ll. Example VI-A 8 PTB 0 300 'Prepared from the reaction of polyhutylene of about 1200 molecular weight with muleic unhydride followed by a reaction with letraethylcne pentamine.

CARBURETOR ICING TEST The anti-icing properties of the additive-containing fuel of the invention were determined in the carburetor icing demonstrator apparatus consisting of a vacuum It is evident from the foregoing data that the novel fuel composition of the invention illustrated by Runs 6 through 11 is outstandingly effective in its carburetor anti-icing and corrosion inhibiting properties. In contrast, related type products exhibited by Runs 2 through 5 inclusive are ineffective in both tests.

The fuels of the invention may contain any additive conventionally employed in gasoline. Tetraalkyl lead, antiknock additives, dyes, anti-oxidants and the like can be beneficially employed without materially affecting the corrosion inhibiting and detergent additive of the invention. Finished gasolines can also contain from about 0.0lto 0.20 volume percent of a polymer, copolymer or the corresponding hydrogenated polymer or copolymer of a C to C unsaturated hydrocarbon having 7 a molecular weight in the range of 500 to 3,500 as described in US. Pat. No. 3,502,451, which disclosure is incorporated in this application, in combination with the corrosion inhibitor and detergent of the present invention. Particularly effective multifunctional fuel compositions are obtained by adding polypropylene and polyisobutylene of 800 to 1100 molecular weight in which R is an aliphatic hydrocarbon radical having from about 8 to 22 carbon atoms, R is a lower aliphatic hydrocarbon radical having from 1 to 2 carbon atoms. R is an aliphatic hydrocarbon radical having from 8 to 20 carbon atoms or an aminoalkyl group of the structure NH (CH or an N -alkylaminoalkyl group of the structure R -NH-(CH where R is an aliphatic hydrocarbon radical having from 8 to 20 carbon atoms and n is an integer from 2 to 6, and R and R each represent a hydrogen atom or an alphatic hydrocarbon radical having from 1 to 20 carbon atoms.

2. A motor fuel composition according to claim 1 in which R and R are aliphatic hydrocarbon radicals having from 10 to l8 carbon atoms.

3. A motor fuel composition according to claim 1 in which R is C1445 secondary alkyl radical and R is a tetradecyl radical.

4. A motor fuel composition according to Claim 1 in which said alkylammonium alkyl alkanephosphonate is C1445 secondary alkylmethyl amonium methyl-n-tet radecylphosphonate.

5. A motor fuel composition according to claim 1 in which said alkylammonium alkyl alkanephosphonate is n-dodecylmethylamonium methyl-n-tetradecylphosphonate.

6. A motor fuel composition according to claim 1 in which said alkylammonium alkyl alkanephosphonate is N'-dodecylaminopropylmethylammonium methyl n-tetradecylphosphonate.

7. A motor fuel composition according to claim 1 in which said alkylyammonium alkyl alkanephosphonate is N-octadecylaminopropylmethylammonium methyl n-tetradecanephosphonate.

8. A motor fuel composition according to claim 1 in which said alkylyammonium alkyl alkanephosphonate is n-tetradecyltrimethylammonium methyl-n-tetradecanephosphonate.

9. A motor fuel composition according to claim 1 containing from about 0.002 to 0.075 wt. percent of said alkylammonium alkyl alkanephosphonate. glass 10. A motor fuel composition according to claim 1 in which said alkylammonium alkyl alkanephosphonate is N-dodecylaminopropylmethylammonium methyl n-tetradecylphosphonate 1 l. A motor fuel composition according to claim 1 in which said alkylammonium alkyl alkanphosphonate is N-octadecylaminopropylmethylammonium methyl noctadecanephosphonater 

1. A MOTOR FUEL COMPOSITION COMPRISING A MIXTURE OF OF HYDROCARBONS IN THE GASOLINE BOILING RANGE CONTAINING FROM ABOUT 0.0005 TO 0.1 WT. PERCENT OF AN ALKYL ALKANEPHOSPHONATE REPRESENTED BY THE FORMULA,
 2. A motor fuel composition according to claim 1 in which R and R2 are aliphatic hydrocarbon radicals having from 10 to 18 carbon atoms.
 3. A motor fuel composition according to claim 1 in which R is C14-15 secondary alkyl radical and R2 is a tetradecyl radical.
 4. A motor fuel composition according to Claim 1 in which said alkylammonium alkyl alkanephosphonate is C14-15 secondary alkylmethyl amonium methyl-n-tetradecylphosphonate.
 5. A motor fuel composition according to claim 1 in which said alkylammonium alkyl alkanephosphonate is n-dodecylmethylamonium methyl-n-tetradecylphosphonate.
 6. A motor fuel composition according to claim 1 in which said alkylammonium alkyl alkanephosphonate is N''-dodecylaminopropylmethylammonium methyl n-tetradecylphosphonate.
 7. A motor fuel composition according to claim 1 in which said alkylyammonium alkyl alkanephosphonate is N''-octadecylaminopropylmethylammonium methyl n-tetradecanephosphonate.
 8. A motor fuel composition according to claim 1 in which said alkylyammonium alkyl alkanephosphonate is n-tetradecyltrimethylammonium methyl-n-tetradecanephosphonate.
 9. A motor fuel composition according to claim 1 containing from about 0.002 to 0.075 wt. percent of said alkylammonium alkyl alkanephosphonate. glass
 10. A motor fuel composition according to claim 1 in which said alkylammonium alkyl alkanephosphonate is N''-dodecylaminopropylmethylammonium methyl n-tetradecylphosphonate
 11. A motor fuel composition according to claim 1 in which said alkylammonium alkyl alkanphosphonate is N''-octadecylaminopropylmethylammonium methyl n-octadecanephosphonate. 